4Suite XML Tools: Includes an XSLT Processor written in Python by FourThought LLC [Open Source].
DataPower Products: DGXT is an optimized software-based XSLT interpreter that is cross-platform and fully compliant with the current XSL specification. The XA35 XML Accelerator is a hardware-based solution that speeds XSLT, XPath, XSD (Schema validation) by 30X or more [Commercial].
Ecrion XF Rendering Server: Uses XSL formatting objects to dynamically create customized PDF, POSTSCRIPT, HTML, GIF, JPEG, or PNG files from XML data [Commercial].
libxslt: XSLT C library developped for the Gnome project [Open Source, MIT].
MDC-XSL: XSLT processor written in C++ [Open source, GPL].
Microsoft XML Downloads: Contains an XSLT engine, which fully implements the XSLT standard [Freeware].
PassiveTeX: A library of TeX macros which can be used to process an XML document which results from an XSL transformation to FO (formatting objects) [LaTex].
Sablotron: Sablotron is an attempt to develop fast, compact and portable XSLT processor. Supported platforms: Linux, Windows NT and Solaris [Open Source, GPL].
Scriptura: A letter, report, and output generator for XSLT/XSLFO documents. GUI Designer for stylesheets, plus an Engine to create XSLT, XSLFO, PDF, XHTML, and PCL5. [Commercial].
ShoXS: a Shorter XSL Syntax: ShoXS is a Shorter Syntax for XSL and this site provides some tools to read XSL files, convert and edit in ShoXS then convert back and save in XSL [Open Source, GPL].
The SAXON XSLT Processor: Java XSLT processor developed by Michael Kay [Open source, MPL].
Tiger XSLT Mapper: Drag and drop XSLT Editor that doesn't require knowledge of XSLT syntax. Developer edition is free. [Commercial]
Unicorn XSLT Processor: XSLT processor for Windows written in C++ [Freeware].
Xalan-C++: XSLT Processor written in C++. A part of Apache's XML project [Open Source].
XML/XSL Portal: Utilities and downloads for XSLT and related developers.
XML::XSL: A server side XSLT processor written in Perl [Open source, GPL].
XSet: An XML property set description of XML 1.0 and XML namespaces that enables XPath based indexing and addressing of the full fidelity grove of an XML document.
XSL Processor for ColdFusion: CFX Tag allows you to perform XSL Transformations with ColdFusion. Free developer edition, commercial sites must purchase a license per server.
XSL Template Designer: Includes a Windows GUI that simplifies designing layouts for complex XML forms and a runtime Engine that merges a layout with XML data to produce a PDF via XSL-FO [Commercial].
XSL Transformations (XSLT) in Mozilla: Information about Mozilla's native XSLT processor. Includes a FAQ and a list of known bugs.
xsl:easy: Transformation tool using built-in graphical XSLT editor to create XML out of arbitrary data and save the transformation result back to other formats [Commercial].
XSLScript: Terse notation for writing complex XSLT stylesheets
Xsltp.pl: Perl CGI XSLT processor [Open Source].